>How do you prevent your mail robot from using too much CPU?

We have timer now in Visual FoxPro. The INI file can be set to any number of seconds you want between each checkup.

>Do you have it go to sleep periodically? Would the FoxPro WAIT command help? Also, how do you know whether an E-mail was successfully sent to the SMTP server? Does MailX Extension handle these issues?

If you plan to deliver at least 5000 emails per day, then you should consider having a dedicated server.

After a sendmail, you can check the error code to see the status.